Wear-resisting surface structure

Abstract

A component comprising a body including a roughened contact surface comprising peaks and valleys, and a conformal coating of a coating material at the roughened surface, wherein the roughened surface has a surface roughness which is such that the valleys define voids in which coating material is entrapped during wear of the component in exposing the body, with the entrapped coating material conferring improved wear resistance.

The invention claimed is: 
     
       1. A component comprising a body including a roughened contact surface comprising peaks and valleys, and a conformal coating of a coating material at the roughened contact surface of the body, wherein the coated surface has a surface roughness which is such that the valleys define voids between peaks of the roughened contact surface of the body, in which coating material is entrapped during wear of the component in exposing the body, with the entrapped coating material conferring improved wear resistance. 
     
     
       2. The component of  claim 1 , wherein the roughened contact surface of the body has a surface roughness ratio R q /R sm  of from about 0.0375 to about 0.0475, wherein:
 R q  is the root mean square roughness parameter defined by: 
 
       
         
           
             
               Rq 
               = 
               
                 
                   ( 
                   
                     
                       1 
                       L 
                     
                     ⁢ 
                     
                       
                         ∫ 
                         L 
                       
                       ⁢ 
                       
                         
                           z 
                           2 
                         
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           ⅆ 
                           x 
                         
                       
                     
                   
                   ) 
                 
                 
                   1 
                   / 
                   2 
                 
               
             
           
         
         where z is the height of the surface measured above the mean level which is a line drawn such that the area of material above the line is equal to the void below the line, and L is the measurement length; and 
         R sm  is the mean spacing of profile irregularities defined by: 
       
       
         
           
             
               Rsm 
               = 
               
                 
                   1 
                   n 
                 
                 ⁢ 
                 
                   
                     ∑ 
                     
                       i 
                       = 
                       1 
                     
                     
                       i 
                       = 
                       n 
                     
                   
                   ⁢ 
                   
                     s 
                     i 
                   
                 
               
             
           
         
         where s i  is the distance between two mean line crossings, and n is the number of peaks within the sample length. 
       
     
     
       3. The component of  claim 2 , wherein the roughened contact surface of the body has a surface roughness ratio R q /R sm  of from about 0.04 to about 0.0475. 
     
     
       4. The component of  claim 3 , wherein the roughened contact surface of the body has a surface roughness ratio R q /R sm  of from about 0.04 to about 0.045. 
     
     
       5. The component of  claim 1 , wherein the roughened contact surface of the body is an electro-discharge machined (EDM) surface. 
     
     
       6. The component of  claim 1 , wherein the body is formed of a carbide. 
     
     
       7. The component of  claim 6 , wherein the carbide is tungsten carbide. 
     
     
       8. The component of  claim 1 , wherein the coating has a thickness of not greater than about 5 μm. 
     
     
       9. The component of  claim 1 , wherein the coating is a coating selected from the group consisting of TiN, TiC, Ti(Al,N), Ti(C,N), and superhard coating materials, including diamond and cubic boron nitride (cBN). 
     
     
       10. The component of  claim 1 , wherein the component is a machine tool. 
     
     
       11. The component of  claim 10 , wherein the component is a cutting tool. 
     
     
       12. The component of  claim 10 , wherein the component is a forming tool. 
     
     
       13. The component of  claim 1 , wherein the component is a seal element. 
     
     
       14. A wear-resisting component comprising a body including a roughened contact surface comprising peaks and valleys, and a conformal coating of a coating material at the roughened contact surface of the body, wherein peaks of the roughened contact surface of the body have a height which is greater than a height of the coating in valleys of the roughened contact surface of the body, thereby defining voids between peaks of the roughened contact surface of the body, in which coating material is entrapped during wear of the component in exposing the body. 
     
     
       15. The component of  claim 14 , wherein the component is a machine tool. 
     
     
       16. The component of  claim 15 , wherein the component is a cutting tool. 
     
     
       17. The component of  claim 15 , wherein the component is a forming tool. 
     
     
       18. The component of  claim 14 , wherein the component is a seal element.